The present invention provides an offloading method and device for enhancing mobility, used for solving the technical problem of poor mobility in the current offloading and network construction solution. The present invention discloses that: a Network Address Translating (NAT) gateway is deployed in an upper layer of a Femto Node B; a dedicated tunnel for transmitting the offloading data between the Femto Node B and the NAT gateway is established; the NAT translation of the offloading data message is performed by the NAT gateway and the offloading data is forwarded through the dedicated tunnel according to a continuation relationship; when a User Equipment (UE) performs a handover across two Femto Node B's due to mobility, it is only necessary to modify the continuation relationship of the UE, without disconnecting and reconnecting the link of the offloading data stream, thereby improving the system's mobility.